Heteroepitaxy of gallium nitride based compound semiconductors on sapphire, silicon carbide and silicon are currently used in light-emitting devices (LEDs), high power devices and high speed radio frequency (RF) devices. Applications include lighting, computer monitors, displays, wide band gap communications, automotive and industrial power sources.
The growth of gallium nitride based devices such as LED structures on a sapphire substrate is a heteroepitaxial growth process since the substrate and the epitaxial layers are composed of different materials. Due to the heteroepitaxial growth process, the epitaxially grown material can exhibit a variety of adverse effects, including reduced uniformity and reductions in metrics associated with the electronic/optical properties of the epitaxial layers. Accordingly, there is a need in the art for improved methods and systems related to epitaxial growth processes and substrate structures.